Electrical connectors for use in locations having potentially hazardous atmospheres are often made so that any exposed electrical components which are being brought into mechanical contact with each other are not energized until after the physical contact has been competed. For this purpose, it is desirable to provide a switch within the connector receptacle and to arrange the switch so that it can be closed only after the components have been joined.
While connectors for this general purpose have been devised previously, such connectors are generally quite complicated and therefore rather expensive to produce. In some cases, the connectors are not fail safe, i.e., it is possible to defeat the switching mechanism and energize the receptacle before insertion of the plug.